Longline fishing is a widely practiced fishing technique. Longlines may employ hundreds of baited hooks deployed along miles of lines. The hooks are intended to catch various target species including grouper, tilefish, and sharks. Unfortunately longlines instead often snare other fish or wildlife, called bycatch, including endangered or threatened marine species such as dolphins and sea turtles. Baited hooks typically stay submerged for hours. Bycaught turtles and other non-target marine species frequently drown because they cannot swim to the surface to breathe. Surviving marine animals and other bycatch may be released, but may die soon thereafter due to physiological stress. Hooked catch and bycatch also are preyed upon by other sea creatures or become injured by entanglement in the fishing gear. Entanglement is aggravated by the normal actions of hooked animals, which generally respond by wriggling, swimming frantically, rapidly changing course, etc. Actions such as these often cause or increase entanglement.
The waters off the west coast of Florida, where longline reef fishing is a prominent industry, serve as valuable habitat for sub-adult and breeding-age loggerhead turtles which swim in the sea and nest on Florida beaches. Loggerheads are found in Florida west coast waters throughout the year. During the last decade, there has been a decline of over 40% in Florida loggerhead turtle nesting. Recently, the National Marine Fisheries Service (NMFS) was sued under the Endangered Species Act for failing to protect threatened and endangered sea turtles in the Gulf of Mexico longline fishery. In response, NMFS ordered an emergency fishery closure to protect sea turtles. Studies showed that nearly 1,000 threatened and endangered sea turtles had been captured between July 2006 and the end of 2007. Under a three-year incidental capture authorization, bottom longliners had been allowed to capture up to 85 loggerheads (42 lethal captures), 26 green turtles, 2 Kemp's ridleys, and 1 leatherback. NMFS observers reported in September, 2008 that the actual catch had been 974 hard-shelled turtles, including 700 loggerheads, with 83% of captures resulting in injury or death to turtles. Fishing personnel and the Gulf of Mexico Fishery Management Council have made numerous suggestions for ways to reduce longline sea turtle captures, but it is unlikely that these changes will significantly reduce the number of bycaught turtles or avoid serious harm to the turtle population.
Fishing may also be carried out by assembling buoys, with attached fishing tackle, into an array. Like longline fishing, there are environmental concerns associated with array fishing methods. Arrays generally include 10, 20, or more buoys. Attending to all the buoys in an array can be challenging, as buoys are often separated by considerable distances and consequently may remain unattended for long periods of time. More frequent attention to buoys requires more boats and more personnel, which adds to costs. Unfortunately, the inability to attend to buoys often results in high mortality of both intentional catch and bycatch. As is the case for longline fishing, mortality in an infrequently attended array may be caused by entanglement, predation by other marine life, or drowning.
Patents or applications relating to fishing include U.S. Pat. Nos. 3,908,299 (Kalberer '299), 4,214,394 (Shogan), 4,437,255 (Reed), 4,581,842 (Kalberer '842), 4,766,688 (Hiles), 4,831,769 (Skille), 5,170,581 (Lyons), 5,261,180 (Foster et al.), 5,881,488 (Canepa), 6,397,510 B1 (Klein), 6,457,896 B1 (deDoes), 6,564,500 B1 (Ames) and 6,708,441 B2 (Dirito) and U.S. Patent Application Publication Nos. US 2006/0230666 A1 (Moffitt) and US 2008/0307690 A1 (Jusseit).
Currently, there is an unmet need for fishing equipment that will reduce harm to turtles and other protected marine life.